As this kind of well-known technology, the “Device capable of suction-adhering to a surface and moving therealong” disclosed in the Japanese patent No. 2689127 and the “Device capable of suction-adhering to a surface and moving therealong” disclosed in the Japanese patent No. 2805614 are known. These patents were invented by the inventor of the present invention.
The Device comprises the main casing, the wheels secured to the main casing as a means for mobility, the negative-pressure suction seal connected to the main casing having the peripheral end portion which is caused to contact the surface of an object, the negative-pressure suction seal which rotates the axis of rotation perpendicular to the object surface as an axis, the negative pressure forming means to discharge externally the liquid contained in the negative pressure area defined by the main casing, the surface and the negative-pressure suction seal, and the vacuum breaker which makes envelopment fluid flow into the inside of the negative pressure area and maintains the pressure of the area to the predetermined vacuum pressure.
That is, the vacuum breaker is a kind of the relief valve for maintaining vacuum pressure to a fixed degree of vacuum.
The main casing must not necessarily be directly equipped with the relief valve. In the suction hose which connects the main casing, and a negative pressure generation means, the portion close to the main casing of the suction hose may be equipped with the relief valve.
In such a device, the energization of the negative pressure forming means causes the liquid inside the said area to be discharged externally, and the pressure of the liquid that acts on the main casing because of the liquid pressure difference between the inside and the outside of the said area is transmitted to the surface of an object via the wheels, such liquid pressure allowing the Device to adhere to the surface. Additionally, the rotation of the wheels by way of a driving means, such as an electric motor, during such adhesion state allows the Device to move along the surface by the action of the wheels.
Further, if the negative-pressure suction seal in which it was equipped with polish components, such as abrasive cloth, is rotated, polish cleaning of the object surface can be carried out.
And suction recovery of the particulates generated in the case of the polish cleaning work is altogether carried out by the action of the negative pressure generation means. In this device, various cleaning on the object surface can be performed safely and efficiently by remote control, without generating particulates.    [Patent Reference 1]
Japan Patent No. 2689127    [Patent Reference 2]
Japan Patent No. 2805614
In order to use the “Device capable of suction-adhering to a surface and moving therealong” disclosed in Japan Patent No. 2689127 and Japan Patent No. 2805614, there are following problems to be solved.
“Device capable of suction-adhering to a surface and moving therealong” is equipped with the negative-pressure regulating means so that the contact pressure of the surface and the negative-pressure suction seal may be maintained by the small value.
However, when the negative-pressure regulating means is not efficient, the torque of the seal to be rotated is increased by increasing of the friction between the surface and the seal. The reaction of the torque of the seal tends to make the device to rotate. Therefore, it is difficult for the device to travel straight.
Accordingly, the subject of the present invention is offering “Traveling device equipped with dual, rotating, negative-pressure suction seals” which is equipped with the means by which the straight travel function of the device is not obstructed when the device travels along the surface of the structures.